Check the listing for details. RTOM Black Hole Single Zone Trigger. Condition: New. Listed at 24.99 USD. MADE EXCLUSIVELY FOR USE WITH THE BLACK HOLE PRACTICE SYSTEM! bh Single-Zone Triggers instantly transform acoustic drum heads outfitted with Black Holes into a hybrid kit. With bh Triggers, the days of requiring mesh heads, tools, and time to transform your acoustic heads into an electronic kit have come to an end. Now, simply snap on and snap off Black Holes equipped with bh Triggers to your acoustic heads and, in seconds, drummers effortlessly transition between acoustic and hybrid playing. NOTE: bh Triggers must be used with TS cables.